Simplify transcript worker ownership and publication boundaries

Let the legacy worker own its filename and completion signal. Remove
manual signal deletion and the unused thread accessor together with
Preview's mutex; both loaders publish pages on the main loop.

Keep save/delete exclusion and release it before notifying observers.
Expose the captured-path reader directly, with account and privacy checks
at main-loop dispatch and publication, and remove the redundant bridge.

5 files changed, 51 insertions, 119 deletions

diff --git a/indra/newview/llchatservicehistory.cpp b/indra/newview/llchatservicehistory.cpp
index 954d534641..c21b5e2935 100644
--- a/indra/newview/llchatservicehistory.cpp
+++ b/indra/newview/llchatservicehistory.cpp
@@ -56,16 +56,6 @@
 #include <set>
 #include <sstream>
 
-// Keep exact-path legacy parsing behind LLLogChat's narrow stitching bridge.
-struct LLChatServiceHistoryAccess
-{
-    static void loadLegacy(const std::string& path, std::list<LLSD>& messages,
-                           const LLSD& parameters)
-    {
-        LLLogChat::loadChatHistoryExactUnchecked(path, messages, parameters);
-    }
-};
-
 namespace
 {
 using namespace LLChatServiceHistoryCore;
@@ -2803,7 +2793,7 @@ LLChatServiceHistory::HistoryResult readStitched(
     parameters["cut_off_todays_date"] = false;
     for (const std::string& path : legacy_paths)
     {
-        LLChatServiceHistoryAccess::loadLegacy(path, legacy, parameters);
+        LLLogChat::loadChatHistoryExact(path, legacy, parameters);
     }
 
     const F64 service_epoch = archive.has_oldest
diff --git a/indra/newview/llfloaterconversationpreview.cpp b/indra/newview/llfloaterconversationpreview.cpp
index 3221abaeca..4f39b65371 100644
--- a/indra/newview/llfloaterconversationpreview.cpp
+++ b/indra/newview/llfloaterconversationpreview.cpp
@@ -52,7 +52,6 @@ LLFloaterConversationPreview::LLFloaterConversationPreview(const LLSD& session_i
     mPageSize(CONVERSATION_HISTORY_PAGE_SIZE),
     mAccountName(session_id[LL_FCP_ACCOUNT_NAME]),
     mCompleteName(session_id[LL_FCP_COMPLETE_NAME]),
-    mMutex(),
     mShowHistory(false),
     mMessages(NULL),
     mHistoryThreadsBusy(false),
@@ -127,9 +126,6 @@ void LLFloaterConversationPreview::setPages(std::list<LLSD>* messages, const std
 {
     if(file_name == mChatHistoryFileName && messages)
     {
-        // additional protection to avoid changes of mMessages in setPages()
-        LLMutexLock lock(&mMutex);
-
         // Preserve the reader's distance from the newest page while asynchronous
         // reloads replace the backing list.
         const S32 old_last_page = mMessages && !mMessages->empty()
@@ -155,11 +151,6 @@ void LLFloaterConversationPreview::setPages(std::list<LLSD>* messages, const std
         getChild<LLTextBox>("page_num_label")->setValue(total_page_num);
         mShowHistory = true;
     }
-    LLLoadHistoryThread* loadThread = LLLogChat::getInstance()->getLoadHistoryThread(mSessionID);
-    if (loadThread)
-    {
-        loadThread->removeLoadEndSignal(boost::bind(&LLFloaterConversationPreview::setPages, this, _1, _2));
-    }
 }
 
 void LLFloaterConversationPreview::draw()
@@ -364,8 +355,7 @@ void LLFloaterConversationPreview::invalidateHistory()
 
 void LLFloaterConversationPreview::showHistory()
 {
-    // additional protection to avoid changes of mMessages in setPages
-    LLMutexLock lock(&mMutex);
+    // Both loaders publish on the main loop, so pages stay stable during rendering.
     mChatHistory->clear();
     if(mMessages == NULL || !mMessages->size() || mCurrentPage * mPageSize >= mMessages->size())
     {
diff --git a/indra/newview/llfloaterconversationpreview.h b/indra/newview/llfloaterconversationpreview.h
index 521acb7d4a..d1228d3332 100644
--- a/indra/newview/llfloaterconversationpreview.h
+++ b/indra/newview/llfloaterconversationpreview.h
@@ -60,7 +60,6 @@ private:
     void showHistory();
     void startLegacyLoad();
 
-    LLMutex         mMutex;
     LLSpinCtrl*     mPageSpinner;
     LLChatHistory*  mChatHistory;
     LLUUID          mSessionID;
diff --git a/indra/newview/lllogchat.cpp b/indra/newview/lllogchat.cpp
index 306d490fff..060352ab4c 100644
--- a/indra/newview/lllogchat.cpp
+++ b/indra/newview/lllogchat.cpp
@@ -48,6 +48,7 @@
 #include <boost/date_time/gregorian/gregorian.hpp>
 #include <boost/date_time/posix_time/posix_time.hpp>
 #include <boost/date_time/local_time_adjustor.hpp>
+#include <mutex>
 
 #if !LL_WINDOWS
 #include <fcntl.h>
@@ -432,55 +433,56 @@ void LLLogChat::saveHistory(const std::string& filename,
         return;
     }
 
+    // Keep open/write/close on one side of the deletion sweep, then unlock before
+    // notifying observers that may read or write transcripts.
+    std::unique_lock<LLMutex> mutation_lock(sTranscriptMutationMutex);
+    llofstream file(LLLogChat::makeLogFileName(filename).c_str(), std::ios_base::app);
+    if (!file.is_open())
     {
-        // Keep the whole open/write/flush/close operation on one side of a Delete sweep.
-        LLMutexLock mutation_lock(&sTranscriptMutationMutex);
-        llofstream file(LLLogChat::makeLogFileName(filename).c_str(), std::ios_base::app);
-        if (!file.is_open())
-        {
-            LL_WARNS() << "Couldn't open chat history log! - " + filename << LL_ENDL;
-            return;
-        }
+        LL_WARNS() << "Couldn't open chat history log! - " + filename << LL_ENDL;
+        return;
+    }
 
-        std::string altered_line = line;
+    std::string altered_line = line;
 
     // avoid costly regex calls
-        if (line.find("/mention") != std::string::npos)
-        {
-            static const boost::regex mention_regex(APP_HEADER_REGEX "/agent/[\\da-f-]+/mention", boost::regex::perl | boost::regex::icase);
+    if (line.find("/mention") != std::string::npos)
+    {
+        static const boost::regex mention_regex(APP_HEADER_REGEX "/agent/[\\da-f-]+/mention", boost::regex::perl | boost::regex::icase);
 
         // replace mention URL with [@username](URL)
-            altered_line = boost::regex_replace(line, mention_regex, [](const boost::smatch& match) -> std::string
-            {
-                std::string url = match[0].str();
-                std::string username = LLUrlAction::getURLLabel(url);
-                return "[" + username + "](" + url + ")";
-            });
-        }
+        altered_line = boost::regex_replace(line, mention_regex, [](const boost::smatch& match) -> std::string
+        {
+            std::string url = match[0].str();
+            std::string username = LLUrlAction::getURLLabel(url);
+            return "[" + username + "](" + url + ")";
+        });
+    }
 
-        LLSD item;
+    LLSD item;
 
-        if (gSavedPerAccountSettings.getBOOL("LogTimestamp"))
-             item["time"] = LLLogChat::timestamp2LogString(0, gSavedPerAccountSettings.getBOOL("LogTimestampDate"));
+    if (gSavedPerAccountSettings.getBOOL("LogTimestamp"))
+         item["time"] = LLLogChat::timestamp2LogString(0, gSavedPerAccountSettings.getBOOL("LogTimestampDate"));
 
-        item["from_id"] = from_id;
-        item["message"] = altered_line;
+    item["from_id"] = from_id;
+    item["message"] = altered_line;
 
     //adding "Second Life:" for all system messages to make chat log history parsing more reliable
-        if (from.empty() && from_id.isNull())
-        {
-            item["from"] = SYSTEM_FROM;
-        }
-        else
-        {
-            item["from"] = from;
-        }
-
-        file << LLChatLogFormatter(item) << std::endl;
-        file.close();
+    if (from.empty() && from_id.isNull())
+    {
+        item["from"] = SYSTEM_FROM;
+    }
+    else
+    {
+        item["from"] = from;
     }
 
-    LLLogChat::notifyTranscriptCreated();
+    file << LLChatLogFormatter(item) << std::endl;
+
+    file.close();
+    mutation_lock.unlock();
+
+    LLLogChat::getInstance()->triggerHistorySignal();
 }
 
 // static
@@ -590,18 +592,6 @@ void LLLogChat::getTranscriptFamily(const std::string& file_name, std::vector<st
 void LLLogChat::loadChatHistoryExact(const std::string& path, std::list<LLSD>& messages,
                                      const LLSD& load_params)
 {
-    if (LLChatServiceHistory::historySuppressed())
-    {
-        return;
-    }
-
-    loadChatHistoryExactUnchecked(path, messages, load_params);
-}
-
-// static
-void LLLogChat::loadChatHistoryExactUnchecked(
-    const std::string& path, std::list<LLSD>& messages, const LLSD& load_params)
-{
     if (path.empty())
     {
         return;
@@ -638,17 +628,6 @@ bool LLLogChat::historyThreadsFinished(LLUUID session_id)
     return finished;
 }
 
-LLLoadHistoryThread* LLLogChat::getLoadHistoryThread(LLUUID session_id)
-{
-    LLMutexLock lock(historyThreadsMutex());
-    std::map<LLUUID,LLLoadHistoryThread *>::iterator it = mLoadHistoryThreads.find(session_id);
-    if (it != mLoadHistoryThreads.end())
-    {
-        return it->second;
-    }
-    return NULL;
-}
-
 LLDeleteHistoryThread* LLLogChat::getDeleteHistoryThread(LLUUID session_id)
 {
     LLMutexLock lock(historyThreadsMutex());
@@ -903,17 +882,11 @@ bool LLLogChat::moveTranscripts(const std::string currentDirectory,
 //static
 void LLLogChat::deleteTranscripts()
 {
-    deleteTranscriptContent();
+    deleteTranscriptContent(gDirUtilp->getPerAccountChatLogsDir());
     LLFloaterIMSessionTab::processChatHistoryStyleUpdate(true);
 }
 
 // static
-bool LLLogChat::deleteTranscriptContent()
-{
-    return deleteTranscriptContent(gDirUtilp->getPerAccountChatLogsDir());
-}
-
-// static
 bool LLLogChat::deleteTranscriptContent(const std::string& directory)
 {
     // Snapshot and remove the exact legacy targets while plaintext writers are excluded.
@@ -1286,8 +1259,7 @@ LLLoadHistoryThread::LLLoadHistoryThread(const std::string& file_name, std::list
     mMessages(messages),
     mFileName(file_name),
     mLoadParams(load_params),
-    mNewLoad(true),
-    mLoadEndSignal(NULL)
+    mNewLoad(true)
 {
 }
 
@@ -1338,7 +1310,7 @@ void LLLoadHistoryThread::loadHistory(const std::string& file_name, std::list<LL
             if (!fptr)
             {
                 mNewLoad = false;
-                (*mLoadEndSignal)(messages, file_name);
+                mLoadEndSignal(messages, file_name);
                 return;                     //No previous conversation with this name.
             }
         }
@@ -1357,7 +1329,7 @@ void LLLoadHistoryThread::loadHistory(const std::string& file_name, std::list<LL
         {
             fclose(fptr);
             mNewLoad = false;
-            (*mLoadEndSignal)(messages, file_name);
+            mLoadEndSignal(messages, file_name);
             return;
         }
     }
@@ -1401,25 +1373,10 @@ void LLLoadHistoryThread::loadHistory(const std::string& file_name, std::list<LL
 
     fclose(fptr);
     mNewLoad = false;
-    (*mLoadEndSignal)(messages, file_name);
+    mLoadEndSignal(messages, file_name);
 }
 
 boost::signals2::connection LLLoadHistoryThread::setLoadEndSignal(const load_end_signal_t::slot_type& cb)
 {
-    if (NULL == mLoadEndSignal)
-    {
-        mLoadEndSignal = new load_end_signal_t();
-    }
-
-    return mLoadEndSignal->connect(cb);
-}
-
-void LLLoadHistoryThread::removeLoadEndSignal(const load_end_signal_t::slot_type& cb)
-{
-    if (NULL != mLoadEndSignal)
-    {
-        mLoadEndSignal->disconnect_all_slots();
-        delete mLoadEndSignal;
-    }
-    mLoadEndSignal = NULL;
+    return mLoadEndSignal.connect(cb);
 }
diff --git a/indra/newview/lllogchat.h b/indra/newview/lllogchat.h
index 468093eff7..5e24a658b3 100644
--- a/indra/newview/lllogchat.h
+++ b/indra/newview/lllogchat.h
@@ -49,7 +49,8 @@ private:
 class LLLoadHistoryThread : public LLActionThread
 {
 private:
-    const std::string& mFileName;
+    // The worker owns its input after the Preview closes.
+    const std::string mFileName;
     std::list<LLSD>* mMessages;
     LLSD mLoadParams;
     bool mNewLoad;
@@ -61,9 +62,8 @@ public:
     virtual void run();
 
     typedef boost::signals2::signal<void (std::list<LLSD>* messages,const std::string& file_name)> load_end_signal_t;
-    load_end_signal_t * mLoadEndSignal;
+    load_end_signal_t mLoadEndSignal;
     boost::signals2::connection setLoadEndSignal(const load_end_signal_t::slot_type& cb);
-    void removeLoadEndSignal(const load_end_signal_t::slot_type& cb);
 };
 
 class LLDeleteHistoryThread : public LLActionThread
@@ -112,6 +112,8 @@ public:
     // Enumerate the ordinary transcript followed by lexical monthly shards, then
     // reuse the canonical parser for each exact path.
     static void getTranscriptFamily(const std::string& file_name, std::vector<std::string>& paths);
+    // Worker reads use captured paths; the caller checks account/privacy state
+    // on the main loop before dispatch and again before publishing the result.
     static void loadChatHistoryExact(const std::string& path, std::list<LLSD>& messages,
                                      const LLSD& load_params = LLSD());
 
@@ -130,7 +132,6 @@ public:
 
     // The success-returning sweep lets durable ChatService deletion remain pending
     // until every legacy transcript target has been removed safely.
-    static bool deleteTranscriptContent();
     static bool deleteTranscriptContent(const std::string& directory);
     static void notifyTranscriptCreated();
     static bool isTranscriptExist(const LLUUID& avatar_id, bool is_group=false);
@@ -141,17 +142,12 @@ public:
     static std::string getGroupChatSuffix();
 
     bool historyThreadsFinished(LLUUID session_id);
-    LLLoadHistoryThread* getLoadHistoryThread(LLUUID session_id);
     LLDeleteHistoryThread* getDeleteHistoryThread(LLUUID session_id);
     bool addLoadHistoryThread(LLUUID& session_id, LLLoadHistoryThread* lthread);
     bool addDeleteHistoryThread(LLUUID& session_id, LLDeleteHistoryThread* dthread);
     void cleanupHistoryThreads();
 
 private:
-    friend struct LLChatServiceHistoryAccess;
-    static void loadChatHistoryExactUnchecked(const std::string& path,
-                                              std::list<LLSD>& messages,
-                                              const LLSD& load_params = LLSD());
     static std::string cleanFileName(std::string filename);
 
     LLMutex* historyThreadsMutex();